Thermal cut-out and circuit-changer.



PATENTED OCT. 16, 1906.

A. O, STIGBERG: THERMAL OUT-OUT AND CIRCUIT CHANGER.

APPLICATION FILED JUNE 3.1904.

22 40 1 I //4 2 M I6? I z 44 4.; 47 3 5 f 40 42 Z fiji 5- E-" I n y- STATES PATENT OFFICE.

ALFRED O. STIGBERG, OF CHICAGO, ILLINOIS, ASSIGNOR- TO vSTROIIIBERG- CARLSON TELEPHONE MANUFACTURING COMPANY,

1 NEW YORK, A CORPORATION OF NEW YORK.

OF ROCHBTER,

THERMAL cur-our AND CIRCUIT-CHANGER.

Specification of Letters Patent.

Patented ct..16, ieoe.

Application filed June 8, 1904. Serial Ho- 210,948.

art for preventing continued and injurious flow of so-called ,sneak-currents.

The object of my invention is to provide more eflicient and more reliable means for opening the circuit to be protected after .a

redetermined interval of undue currentow therethrough and for grounding or dischargingsaid current from the line.

My invention consists of an im roved heatcoil associated with improved eat-res on- 2 5 sive means for controlling the positions 0 circuit-changing contact-springs.

The heat-coil consists of a sleeve of insulating material through which passes a heatconductin o windin w 'ch is comiected with one terminal to t e stem and with its other terminal to a metallic cap fitting over one end of the sleeve. When the coil is in osition, this sleeve engages a line-spring, w ile the other end of the rod engages the spring connecting with the switchboard apparatus or other apparatus to be protected. Anarrester-s ring, ermanently connected. at its end wit the inc-spring, en ages one terminal of a light- 40 ning-arrester, the other terminal of which engages a ground-bar, and thus a line may be relieved from lightning or other static charges. This arrester-spring is provided at its upper end with a sleeve or slide having an o ening through its walls for the reception of t e end of the heat-coil rod, this opening, however, being large enough to prevent contact of the arrester-spring with the rod. A disk of heat-responsive material is adapted to slide through this sleeve and normally blocks the passage of the rod through this opening, and the rod when thus held is pressed at its rod or stem surrounded by a I other end into contact with the switchboardspring and against the force of a pressurespring engaging the switchboard end of the heat o 'As' abnormal current flows through the line and winding of the heat-coil the heat (generated by the coil is conducted by the ro to the heat-res onsive disk, which becomes softened and afiows the pressurespring to force the rod therethrough, and the rod thereupon becomes disengaged from the switchboard-spring to open the circuit. The line-spring is at the same time carried backward to engage a grounded stem normally disconnected therefrom, and-the undue current is then led to ground. The pressurespring may also on age a contact-spring upon release of the T0 to close a local circuitv through an annunciator or alarm mechanism.

The heatcoil of my construction may be used continuouslywlthout removal from the relatively stationary. Upon puncture of the heat-responsive disk the coil is pulled outwardly and the heat-responsive diskraised.

or lowered in the sleeve to resent an i1npunctured' spot to the end of tl e rod, and the circuit-changer is again in operative condition.

I- shall describe my invention more clearly with reference to the accompanying drawings, in which V Figure 1 shows an elevation view of my inventlon. Fig. 2 is a top view thereof, and Fig. 3 is an enlarged longitudinal sectional view of the. heat-coil and heat-responsive mechanism. 7

I have shown onl a set of opposite springs secured to a oun bar or frame 1, it being understood t at any number of spring sets ma be connected to the ground-bar in a row. A inc-spring 2 and the lightning-arrester spring 3 are provided for each switching mechanism, the lower ends of these springs being permanently conductively connected. A-awitch-spring 4, a pressure-spring 5, and a contact-spring 6 are also provided, all these springs being assembled and secured at their lower ends to the ground-bar 1 b means of bolts 7 7 and clam ing-nuts 8 8, isks 9 9, of insulating materia bein interposed between the s rings to insulate t em from each other and om the ground-frame, the springs 2 and springs, the parts thereof being at all times sure-spring is provi ed with an opening 1 1.

3, however,.:as before stated, being inconductive enga ementf. The 'hnesprmg .2 s provided wit an annular ocket and the pres- The heat-c011 consists of a c lindrical bushing 12, of insulatingma'teri having ,closed ends. A bushing 13 extends from the outer end and is adapted to pass through the o enmfi 11. Aheat-conductingrod 14 passes till-o this bus 1 3,and through the inner end 0 the heat-co' which inner end is provided with a metallic cap 15,-insulated from pressure-spring.

the rod. The heat-coil winding 16 connects with one terminal to this cap and with its other terminal to the heat-conducting rod. The cap when the heat-coil 1s in position is diaposed in the pocket 10, while the bushing 13- passes thro h the opening 11 on the lfiightning-arrester 1 7 may e clamped between the upper end-of the spring 3 and a Tplate 18, extending from the e up ound-bar. v er end of the spring 3 is bent to form a bri ge 19, which carries a sleeve. or slot 20. .An opening 21 'asses through the walls of the sleeve and is a apted for the passage the'rethrough of the inner end of the heatconductingrod, this opening,

however, being large enough to prevent 'contact of the rod with the walls thereof. A disk or plate 22 of heat responsive, and preferably insulating, material, is adapted to slide within I to block the rod through t lightmng-arrester in p .cause good electrica .resterin place.

from the line-spring 2 through the heat-coil this grounded stem 23, and the springs 2'and' 3 have a tendency normally to se ara'te from each other,- whereby spring 3 clamp the ace and spring'2 will contact between the ocket 10 andthe cap 15 of the heat-coil. en the heat-coil is in lace and held by the heat-responsive disk, llll spring 5 willbe transmitted through the rod and heat-responsive disk to the spring 3 .to 1

assist in securely clamping the lig Upon abnormal current flow win and to the SWltGhbOfll'drS the heat g ier'ated by the wind' 16 will b ii conducted by the rod- 14 to the eat-responsive disk 22, which becomes weakened, whereupon the pressure of sp 5-will force the rod through-the disk 22, whereupon this rod becomes-disenga 'ed from the s thecircuit to t e switchboar ratus to be protected.- At the ring 4 to break or other appa same time the 6 5 line-spring engagethe grounded stem or e pressure of the.

stud 23, and the undue current will be discharged from the line to ground. A local circuit containing a bell 26 or other alarm or indicating mechanism and asource of current '27 may be bridged across the pressure-spring 5 and the contact-spring 6, which upon puncture of the disk 22 will engage each other to close a local circuit and to sound the .alarm.

The apparatus may be restored to 1ts normal operative condition by withdrawing the heat-coil a sufficient distance to allow the disk '22 to be raised or lowered to present an unpunctured spot to the end of the heat-conducting rod, and the sprlngs Will be returned td-their normal positions. As the heat-coil parts are permanently relatively stationary, it is unnecessary to remove the heat-coil from the s shoul the" heat-'coil become mechanically injured or its burned or broken.

This is a distinguishmg and novel feature over prior heat-coils, in which parts were relatively this becoming necessary only.

movable upon abnormal current-flow and which it was necessary to remove from the springs to return the parts to their n ormal position. Dependin upon the position'of theheat-responsive' isk and the strength of the spring 5, thisdisk may be made of any thickness, and the adjustment'inthis can be made very delicate.

Many changes may be made in the arrangxi- Inentof the switching-springs and in the construction of the heat-c011 and-heat-responsive parts without departing from the s iritof the mventioh. I do not wish, there ore, to be limited to the exact arrangement as shown.

-' I claim as new, however, and desire to secure by Letters Patent v 1. In a thermal cut out and circuitchanger, thecombination with a heat-coil, of

a terminal spring connected with one termina'l'of said coil, a second terminal-spring,-

heat-responsive means external to said heatrcoilfor normally retaining the' other terminal of said heat-coil in contact with said terminal spring, and means upon abnormal current-flow. through said heat-coil for causing 'said-heatresponsive means to releasesaid other-termina from said second terminal spring I I '2. Ina thermal cut-out, the combination with a'heat-coil, of a terminal spring con-.

nected with oneterminal of said coil, a rod passing throu 11- said heat-coil andconnected with the other terminal thereof, a second terminal spring, heat-responsive material engaging one end of said rod to maintain the other end thereof in contact with said second terminal spring, and meansupon abnormal currenflflow throu h said coil for releasing said rod from said heat-responsive material. and from said second terminal sp'r'. a thermal cut-out, the combination sagas with a heat-coil, of a terminal ring engaging one end of the heat-coil aii d connected with one terminal thereof, a ,rod assing through said heat-coil for conducting t e heat generated thereby, a second terminal spring, a pressure-spring engaging the other end of said heat-coil, and a heat-responsive mass, said pressure spring serving to'firmly press said rod against said heat-res n'srve mass, the other end of said rod being connected with the other terminal of said heat-coil and with said second contact-spring, abnormal current-flow. through said heat-coil causing disengagement of said rod from said heatresponsrve mass and from said second terminalsprirfi.

4. In a ermal cut-out, the combination with a heatcoil, of aterminal spring engaging one end thereof and'connected with one terminalthereof, a rod passing through said heat-coil c'onnectedwith the other terminal thereof, a second terminal spring normally engaged by the end of said rod,'a late of heat-responsive material dis osed in the path of the other end of said to and means upon abnormal current-flow through said heat-coil for causing said rod to] ass through said heat-responsive materra to. disengage said rod from said second terminal spring. a

5. In a thermal cut-out, the combination with a heat-coil, of a terminal spring engaging one end thereof and connected with one terminal thereof, a heat-conducting metallic rod passing through said heat-coil and connected with the other terminal thereof, a second terminal spring engaging one end of said rod, a pressure-s ring enga ing the other end of said, heat-coi and ten ing to disengage said rod from said second terminal spring, and a heat-responsive mass normally disp'osedbefore the other end of said rod to prevent said pressure-spring from disengaging said rod from said second terminal spring, abnormal current-flow through said heat-coil causing the release of said rod from said heat-responsi ve mass and from said second terminal s ring.

6. In a therma cut-out, the combination with a heat-corlyof a terminal spring engaging one end thereof and connected with one.

terminal thereof, a heat-conducting rod extending through said heat-coil and connected with the other terminal thereof, a second terminal 5 ring adapted to engage one end of said ro a pressure-spring engaging the other end of said heat-coil and tending to move said heat-coil to prevent engagement of said rod with said second terminal spring, and a plate of heat-responsive material normally engaging the other end of said rod to revent dise ement ofsaidrod from sai second termina spring by said pressure-spring, abnormal current-flow through said heat-responsive plate to allow said as sure spring to disengage said rod from said secon I terminal spring.

7. In a thermal cut out, and circuitchanger, the combination with a heat-coil, of a terminal spring engaging one end thereof and connected with one terminal thereof, a rod exten thro' h said heat-coil .and connected wit the ot er terminal thereof, a second terminal spring, a pressure-spring engaging the other end of said heat-coil and tending to disengage said rod from said second terminal spring, said terminal springs and pressure-spring .being insulated from each other and secured to a groundplate, a plate of heat-responsive material normally engaged by the other end of said rod to pre vent said pressure-spring from disengaging 'said rod from said second terminal s ring,v

abnormal current-flow through said eatcoil causing said rod to be released om said heat-res onsive plate and from sai second termina -spring, and'means for connecting said first terminal spring withsaid groundplate upon the release of said rod,

8. In -a thermal cutout' and circuitchanger, the combination with a heat-coil, of a terminal spring engaging one end thereof and connected with one terminal, a metallic rod passi throu h said heat-coil and connected wit the ot er terminal thereof, a second terminal spring normally engaging one end of said rod, a switching-spring tendin to disengage said second spring from said r0 a heatresponsive mass normally engaging-the other end of said rod to maintain said rod in engagement with said second terminal spring, abnormal current-flow through said heat-coil causing the release of said rod from said heat-res onsive massand from said second termina spring, a ground-plate, and means for causing said first terminal spring to be connectedwith said ground-plate upon release of said rod. V

9. In a thermal cut-out, the combination with a heat-coil, of a terminal spring con nected with one terminal thereof, a metallic rod passing through said coil and connected with the other terminal thereof, saidrod bein permanently stationary relative to the ot er parts of said heat-co? a second terminal spring normally engaged by said rod, a switching-spring tending to disengage said secondspring from said rod and a heat-responsive mass normally engaging the other end of said rod to maintain connection of said rod with said second terminal s ring abnormal current-flow vthrough sai coil causing release of said rod, from said heatresponsive mass whereby said switchingspring ma break the connection between said secon terminal spring and said rod.

10; In a thermal cut-out, the combination with a heat-coil, of a terminal spring consaid heat-coil causing said rod to pass through 1 nected with one terminal thereof, a metallic rod passing through said coil'and connected with the other terminal thereof, said rod being permanently stationar relative to the ot er parts of said heat-co a second terminal spring normally engaged by said rod, a

spring with said ground-plate upon release of i said rod. I

11. In a thermal cut out and c' cuita terminal spring connected with one terminal thereof, a metallic rod passing through said heat-coil andpermanently stationary relative thereto and connected with the other terminal'thereof, a second terminal s ring normally engaging said rod, a switc 'ng-' spring tending to. disengage said second spring from said rod and a plate of heat-reby said switching-spring.

- said heatacoil and permanently stationary sponsive material normally disposed before t e other'end of said rod to maintain said rod in engagement with said. second terminal spring, a normal current-flow through the said coil causing said rod to-puncturesaid heat-responsive plate to allow disengagement of said'rod from said second terminal spring 12. In a thermal cut out and circuitchanger, the combination with a heat-coil, of

a terminal spring connected with one terminal thereof, a 'metallic rod passing through relative Y thereto and. connected with the other terminal thereof, a second terminal 4 5 spring'normall engaging said rod, a switching-spring ten mg to disengage said second spring from said rod, a plate of heat-responsive material normally disposed before the other end of said rod to maintain said rod in engagement with said second terminal spring,

'- abnormal current-flow through the said coil causing said rod to puncture said-heat-responsive plate to allow disengagement of said rod from said second terminal spring by said switching-spring, aground-plate upon which said terminal springs are mounted, and means for connectin said first terminal spring with saidgroun -plate upon release of 13. In a thermalcut-out, the combination with a heat-coil, of a terminal sp engaging 'oneend thereof and connecte Wit one terminal thereof, a metallic rod passing through said coil and permanently stationary with respect thereto and connected with the; other changer, the combination with a heat-coil, of

terminal thereof, a second terminal spring normally engaging one end of said rod, 9.

switching-spring tending to disengage said second terminal spring from said rod, a heat responsive mass normally disposed against the other end of said rod to prevent disengagement of said second terminal spring from said rod, abnormal current-flow through said coil causing softening of said heat-responsive mass to allow said rod to be pressed into said mass by said switching-s ring, whereby said rod becomes disengaged from said second terminal spring.

14. In a thermal cut out and circuitchanger, the combination with a heat-coil, of a terminal spring connected with one terminal thereof, a rod passing through said coil and connected with the other terminal thereof, a second terminal spring normally engaging one end of said rod, a-switching-spring tending to disengage said rod from said second ter' minal spring, a sleeve disposed at the other end of said rod, an opening through the walls of said sleeve, and a plate of heat-res onsive material adapted to pass through sai sleeve to engage the other end ofsaid rod to normally detain said rod in engagement. with;

said second terminal spring against the action of said switchin spring, abnormal current-flow'through said coilcausing said rod to pass through said late of heat-responsive material to allow re ease of said rod fro said second terminal spring.

15. In a thermal cut-out and circuit' changer, the combination with a heat-coil, of a terminal spring connected with one terminal thereof, a metallic rod passing through saidcoil permanently stationary with' respect to said coil and connected with the other terminal thereof, a second terminal spring normally engaged by one end of saidrod', a switchingsp rin tending to disengage-said second ter-.

said rod to maintain said rod in engagement with said second terminal sprin against'the action of saidswitching-s ring, a normal current-flow through said co causing said switchingprin to move the rod to puncture said plate ofeat-responsive material, whereby said rod becomes disengaged from said sec- 0nd terminal spring, and means for causin saidfirst terminal spring to be connected wit said ground-plate upon release of said rod.

16. Ina t ermal cut-out, the combination with a heat-coil, of a terminal spring engagingoneend thereof and connected with one ioo terminal thereof, a ressure-s ring engaging the other end of sai heat-eoi a rod passing through said coil and connected with the other terminal thereof, a'second terminal spring, said ressure-spring tending to move said coil to. isengage said rod from said second terminal spring, a heat-responsive mass normall disposed against the other end of said ro to nvent diseng ement of said rod from sai second termin spring by said pressure spring, abnormal current flow through said coil causing softening of said heat-responsive mass, whereby said pressurespring may carry the heat-coil to cause said rod to enetrate into said heat-responsive mass, w ereby said rod becomes disengaged from said terminal spring.

17. In a thermal cut-out, the combination with a heat-coil, of a terminal spring engaging one end thereof and connected with one terminal thereof, a (pressure-s ring engaging the other end of sai heat-coi a rod pass' 'thro h said heat-coil and connected wit the ot er terminal thereof, a second terminal spring normally engaging one end of said rod, said pressure-spr tending to disengage said rod from said second terminal spring, a plate of heat-responsive material, and means for normally disposing said plate winding from said terminal springs, and

electrically non-conductive heat-responsive material tending normall to resist disconnection of said winding om said terminal spr ngs, abnormal current-flow causing said heat-responsive material to be unable to resist disconnection of said winding from said terminal springs by said switchi -spring. 19. In a thermal cut-out, the com ination witha heat coil structure comprising a windln'glinclosedby a shell and a heat-conduct' ro exten through said wind' an shell, termma springs associated wit said heat-coil structure, means tending to bodily move said heat-coil structure in one direction and an electrically non-conductive heat-responsr've element adapted to prevent such movement of the heat-coil structure and to maintain connection of the terminals of said with said terminal Asp abnornial current-flow through the, win caus- 5 ing said heat-responsive-member to e unscans before the other end of said rod, abnormal able to prevent movement of the heat-coil structure, whereby the connection of said winding with one of the-terminal springs is,

broken.

20. In a thermal cut-out, the combination with a heat-coil, of terminal springs associated therewith, means tending to bodily move the heat-coil to disconnect said heatcoil from circuit with said terminal springs, and a heat-responsive member of insulating material and adapted under normal conditions to resist disconnection from circuit of said heat-coil by said means, abnormal current-flow causing said heat-responsive memher to be rendered unable to resist disconnection of said heat-coil from circuit with said terminal springs.

21. In a thermal cut-out, the combination with a heat-coil structure composed of a winding surrounded by a shell conducting member extendirhgmlgirough said shell and winding, said win shell and heat-conducting member be' relatively immovable of terminal springs or normally enga the terminals of said wind1ng, a switc g-spring tending to bodily move the and a heat-' heat-coil structure in one direction to disconr nect one of the winding-terminals from the corresponding terminal spring, and an abutment of heat-responsive material adapted to normall resist the bodily motion of said heat-coi structure and the consequentdis connection of said winding from circuit, ab-

normal current-flow through said windmg' causing said abutment to be rendered incaable of resisting the bodily movement of the eat-coil structure, where y said 1s disconnected from circuit with said terminal with a heat-coil structure comprising a winding surrounded by a shell and a heat-conducting rod extending through said shell and winding, of a supporting-spring from which said heat-coil structure is supported, term1 nal' springs between which the heat-coil structure 18 disposed and with which the ter- 22. In a thermal cut-out, the combinationminals of the winding are normally connected, said supporting-spring tending to bodily move the eat-coil structure to break the connection between one terminal spring and the winding, and an abutment o sponsive material engaging the end of said conducting-rod conditions to resist the bodily movement of the heat-coil structure where y to maintain the connection of the in circuit, a

normal current-flow throu sive member whereby said member is renheat-reand adapted under normal the causing heating of the rod and heat-respon I 2 5 dered incapable of resisting the bodily move- 1 ment of said heat-coil structure, whereby said win is disconnected from circuit.

23. In a t ermal cut-out, the combination:

with a heat-coil structure comprising a windsaid winding,'a ground connection adapted for engagement with the first terminal spring, said switching-spring tending to bodily move the heat-coil structure to cause connection of I the first terminal spring with the ground connection and disconnection of the other terminal of the win 7 from the second terminal spring, and an autment of heat-respoir-v v sive material engaged b the end of said heata conducting rod and apted under normal conditions to resist bodily movement of said heat-coil structure to maintain said winding in circuit and .to prevent grounding of the first terminal spring, abnormal current-flow through the wlnding causing said rod and heat-res onsive member to be heated whereby the eat-responsive member is rendered incapable of reslsti movement of said heatcoil structure, there y allowing grounding of the first terminal switch and disconnection 7 from circuit of the winding.

In witness whereof I hereunto subscribe my name this 1st day of June, A. D. 1904. 1 ALFRED O. STIGBERG. Witnesses:

CHARLES J. Sonmnr, HARVEY L. Hanson. 

